Improvement in steam-pressure gages



J. V. IEPSON.

Steam Pressure-Gage.

Patented Nov. 29, 1864.

N. PETERS Phuwumoynpw. wminmm u4 c UNITED STATES PATENT EErcE.

JOHN VIVIAN JEPSON, OF NEW YORK, N. Y.

IMPROVEMENT IN STEAM-PRESSURE GAGES.

Specification forming part of Letters Patent No. 45.247, dated November29, 1864.

To all whom it may concern:

Be it known that I, JOHN VIVIAN JErsoN, a native of England, nowresiding in the city, coun ty, and State ot' New York, have invented'certain new and useful Improvements in Pressure-Gages; and I do herebydeclare that the following' is a i'nll, clear, and exact description ofthe same, reference being had to the accompanying drawings, in which-Figure l represents a front elevation of a steam-pressure gageconstructed according to my invention. lili g. 2 represents a view ofthe same with the dial and index removed and with the diaphragm and theparts adjacent thereto in section, and Fig. 3 represents a transversesection ot' certain parts indicated by the same letters of reference asthe same parts in the other two gures.

The object ot' my invention is to simplify the construction ofpressure-gages and to increase their efficiency.

To this end the iirst part of my invention consists ofthe combinatiomina pressure-gage, o1" a piston to receive and transmit the pressure, a'flexible diaphragm to pack the piston, a spring to resist the pressure,and an index and dial to indicate the amount ot' pressure, thiscombination :operating in such manner that the piston Vrod acts directlyon the spring, which, operating both as a spring and lever, not onlyresists the movement of the piston directly, but also transmits themovenient to the index-gearing'.

rlhe second part of the invention consists of the combination of thepiston which receives the pressure and the spring which resists it withthe toothed sector and pinion which operate upon the index through theintervention of a slide, which, being a means of adjustment between thespring and the index, permits the movement of the index to be regulatedwithout adjusting the spring, and also permits springs of the same forceto be employed in the construction ot gages indicating dift'erent rangesof pressure with about the same angular movement ofthe index.

The gage represented in the accompanying drawings embodies my invention.It has a case, A, ofthe usual circular form, to contain the dial B, theindex O, and other parts of the gage, and it is closed at one side by aglass plate secured by a iianged ring and screws, as usual. At the lowerside ot' this case there is an internal projection or block, D, to whichthe cylinder E, in which the piston F works, is screwed. The lower' endof the cylinder is provided with a iange, g g, which is coupled byscrews h to the flanged head J of the pipe which communicates with thereservoir ot' fluid whose pressure is to be measured.

The piston F is iitted to move freely in the cylinder E, and it restsupon a diaphragm, M,

for the piston-rod. The upper end of the pis`I ton-rod is arranged tobear directly against a strong spring, N, having the form 'of an arm orlever projecting from one side of the' case, to which the shank a u, ofthe spring is secured by screws b b and a cross-bar, c, so that thespring is iixed rigidly in its position. rlhis lever-spring projectsbeyond the end ot' the piston-rod, and its projecting end is fitted witha slide, l), which can be moved along the leven spring for the purposeot' adjusting the gage, and can be secured to it in any requiredpcsition by a clamp-screw, d. he slide has a pivot, e, projecting from011e of its sides in a position to enter into the slot l ot' an arm,fit, which is pivoted at one end to a bracket, S, secured to the back ofthe gage-case, and is titted at the other end with a toothed sector, T.The teeth of this sector engage in those ot' a pinion, U, secured to thearbor which carries the index,so that the movement of the spring Noperates the index. In order to take up the play of the gearing, theindex-arbor is pron vided with a spiral spring, Y, of the usualconstruction.

When this gage is put in use, the pressure of the tiuid upon the underside of the diaphragm M acts against the piston F, and is resisted bythe lever-spring N, and, as the lever-spring N is stift', thev piston ispermittedl to move but a small distance for the total. amount ofpressure which the machine is arranged to indicate 5 hence the flexibledian phragm M is but slightly curved by the pressure, and as thecurvature thus produced is sov slight that the resistance ot' thematerial of the diaphragm to extension is scarcely brought into action,the diaphragm operates substan tially as a frictionless packing, toprevent the leakage at the piston. As the spring N is stift and rigid,it is not appreciably. affected by the sudden movement of the gage or byjars; hence the 'gage may be connected With a locomotive boiler in rapidmovementwithout the oscillation of the machine upon its springsproducing an appreciable effect upon the spring or the index controlledby it, and consequently the Wear of the parts due to continuedoscillation is avoided. Moreover, as the pisto11rod acts directly uponthe spring, and the latter acts both as a spring to resist the pressureand as a lever to operate the sector and pinion which actuate the index,the construction of the parts is simple, and the cost is less than itwould be if a greater number of parts Were used to perform the requiredfunctions.

The interposition of the slide between the spring and index-gearingpermits the regula tion of the movement of the index Without adjust-ingthe spring; hence the spring may be rigidlyT secured to the case of theinstrument,

and the use and cost of means of adjusting it may be dispensed With.Moreover7 springs of the same force may be employed in the constructionof gages of different ranges of pressure but with the same movement ofthe index, because the slide may be adjusted to produce the same angularmovement of the index with a greater or less movement of the spring, asmay be required.

What I claim as my invention, and desire to secure by Letters Patent,is-

l. The combination, in a pressure-gage, of

the piston, ilcxible diaphragm, spring, index,

and dial, substantially as set forth.

2. The combination ofthe piston and spring with the toothed sector,pinion, and index through the intervention of a slide, substan;7 tiallyas set forth.

In testimony whereof' I have hereunto set my hand.

JOHN VIVIAN JEPSON. Witnesses: f

JAMES O. MoRsE, EDMUND O. GAY.

